| 摘要 |
PROBLEM TO BE SOLVED: To suppress response delay of fuel pressure in a high pressure accumu lator by elongating an opening period of a changeover valve which changes over a low pressure accumulator with the high pressure accumulator during fuel i.njection in a transient operation, and increasing an inflow amount to the low pressure accumulator for decreasing the pressure. SOLUTION: High pressure fuel pressurized by a fuel pump 1 is stored first in a high pressure accumulator 3, supplied to an injector 9 through a changeover valve 5, a fuel passage 10a, and then stored in a low pressure accumplator 4 connected to a fuel passage 10a through a branch passage. An electronic control unit 8 opens the changeover valve 5 so as to flow the fuel in the high pressure accumulator 3 to the low pressure accumulator 4, and opens a pressure control valve 34 so as to obtain a set value of the fuel pressure in the low pressure accumulator 4. The ECU 8 increases an inflow amount of the high pressure fuel from the high pressure accumulator 3 to the low pressure accumulator 4 during transient operation where the command pressure of the high pressure accumulator 3 is going to decrease, positively reduces fuel pressure, makes the fuel pressure reach the command pressure speedily, and suppresses response delay of actual pressure to the command pressure. |
